多工况下结构拓扑优化设计

考虑单元删除和增加对结构应力约束的影响，提出了一种新的多工况下结构的双方向渐进优化方法．首先，基于在结构孔洞或边界周围附加人工材料的思路，建立了结构优化模型和应力灵敏度公式．然后，结合结构应力和应力灵敏度，给出了多工况静力载荷下考虑静应力约束的结构优化准则和算法．开展了结构仿真设计，结果表明给出的方法是正确和有效的，并具有较好的工程应用价值．     

D301树脂对酚类的吸附热力学研究

测定D301树脂对环己烷溶液中苯酚的吸附等温线，利用热力学函数关系计算了等量吸附焓，吸附自由能和吸附熵，等量吸附焓在30kJ/mol-35kJ/mol之间，推测吸附过程为氢键吸附。比较D301树脂对水溶液和环己烷溶液中苯酚的吸附性能，及D301树脂对环己烷溶液中苯酚和邻硝苯酚的吸附性能，进一步讨论了D301树脂对酚类物质吸附中的氢键作用。     

Determination of bioelectrochemical parameters of red cell using a piezoelectric crystal sensor

Based on the impedance behavior of red cell at high frequency, the frequency response of series piezoelectric crystal sensor in the red cell suspension was derived and verified experimentally. A method of using piezoelectric crystal sensor to determine the conductivity of the interior of the cell was proposed. The experimental results show that the mean conductivity of rabbit red cell cytoplasm was 0.269 S/m and the mean shape factor of red cell was 2.05.     

树枝状高聚物的合成概况

树枝状高聚物可通过收敛法与发散法等方法合成。本文以树枝状高聚物的组成结构分类综述了最近树枝状高聚物的合成情况     

剪切干涉仪与哈特曼波前传感器的波前复原比较

对横向剪切干涉仪和哈特曼波前传感器的波前探测和复原进行了类比推导和仿真计算。结果表明,在相同输入波前、相同探测面元、相同拟合函数及阶数的情况下,横向剪切干涉仪的波前复原能力比哈特曼波前传感器强。主要原因是前者对波前的间接采样所包含的波前信息大于后者,并且前者比较容易增大对波前的采样。     

A SINGLE STEP SCHEME WITH HIGH ACCURACY FOR PARABOLIC PROBLEM

1 IntroductionConsider one-dimellsional parabolic problem in fl = (0, 1)and its weak formulatioll: find u(t) E S0 = {v 6 H'(fl), v(0) = 0} 8uch thatwhere the coefficients a(x) and b(x) are independent of t, Au = --(au')' ha, a(x) 2 ao > 0, b 20, and bilinear fOrm A(u, v) = fol(au'V' buv)dx i8 So-coercive, i.e. A(u, v) 2 ullu1li, u ESO, u > 0.Make in n = (0, 1) a subdivision: xo = 0 < x1 < x2 <.' < xn = 1. Set an elenlentry = (xj--l, xj), nddpoint xj--1/2 = (ry n--1)/2 and steplengt…     

改进桥路型高温超导限流器的实验研究

本文介绍了单相基本桥型高温超导限流器的基本工作原理,及其参数变化对限流特性的影响.在此基础上研究应用于电力系统中的改进桥路型高温超导故障限流器实验室样机,正常工作情况,在电桥上引入直流偏置电流,不出现限流现象;短路故障情况,整流桥中的直流偏流影响限流效果,在桥路上引入限流电阻,使故障电流限制到预定的范围.研究了该限流器的工作原理,分析限流参数的变化对其限流特性的影响.实验表明,该限流器有很好的限流和重合闸能力,能显著减少暂态及稳态的故障电流。     

新型桥路型高温超导故障限流器的仿真研究

研究应用于三相电力系统中新型桥路型高温超导故障限流器.正常工作情况,在电桥上引入直流偏置电流,不出现限流现象.在短路故障情况,整流桥中的直流偏流影响限流效果,将二极管和偏压电源从限流器中退出运行,超导线圈的电感能限制故障电流峰值和稳态值,利用限流电阻与超导线圈串联限流,进一步提高其限流能力.分析了限流器的工作原理和限流特性.仿真结果表明,该限流器有很好的限流和重合闸能力,能显著减少暂态及稳态的故障电流,有效提高系统动态稳定性和电网电能质量.     

An experimental study of aero-optical aberration and dithering of supersonic mixing layer via BOS

The optical performance of supersonic mixing layer is heavily deteriorated by the aero-optical aberration and dithering of coherent structures, but current measuring methods limit the spatiotemporal resolution in relevant studies. A high resolution whole-field aero-optical aberration and dithering measuring method based on the Background Orient Schlieren (BOS) technique was studied. The systematic structure, sensitivity and resolution of BOS are analyzed in this paper. The aero-optical aberration and dither...